THE MESOZOIC FLORA OF PERU * 

 By EDWARD W. BERRY 



DISTRIBUTION AND CHARACTER OF THE MESOZOIC ROCKS 



Mesozoic rocks are very widespread in Peru and are 

 especially prominent in the Cordillera Occidental, especially 

 between latitudes 5 and 13 South. Beyond this the enor- 

 mous amount of volcanic material almost entirely masks the 

 sedimentary rocks, but the presence of Cretaceous limestones 

 at Sta Lucia identical in character with those farther north 

 suggests similar conditions beneath the great volcanic field of 

 Southern Peru. These rocks probably also continue north- 

 ward across Ecuador and tie up with the Mesozoic series in 

 the Columbian Andes, and all are a part of the Mediterran- 

 ean, Urgonian or Comanchean province of the Western 

 Hemisphere. Most of the Jurassic and Cretaceous horizons 

 are represented, but the details are still obscure despite the 

 extensive recent contributions of Steinmann and Lisson to 

 the paleontology of the beds of these ages in Peru. 



The question of Mesozoic climates, particularly the great 

 latitudinal range of the so-called Wealden flora gave an en- 

 hanced interest to the excellent sections of Mesozoic to be 

 found near Lima and admirably described by Senor Lisson. 1 



Through the courtesy of Senor Jose Bravo, the genial 

 director of the Cuerpo de Ingenieros de Minas the Williams 

 Expedition was enabled to study and collect from the section 

 exposed on San Lorenzo Island. 



This island, to which the port of Callao owes its harbor, 

 is about 10 km. long from northwest to southeast, about one- 

 third that width, and about 5 km. off La Punta. It rises to 

 a maximum height of 1,326 feet and consists entirely of Mes- 



* George Huritington Williams Memorial Publication No. 16. 

 1 Lisson, Carlos I., Contribution a la Geologia de Lima y sus 

 Alrededores. Lima 1907. 



